Internal-combustion engine



March 9,1926. 1,576,357-

v 7 V. U. D. PIERCE INTERNAL COMBUSTION ENGINE Filed July 5, 1917 awuMWo t Vm'roN U1) iERCE DOUBLE GLEHRENCE SPRCE Patented M 9, 1926,

um'rso S -ms PATENT OFFICE.

YINTON U. ID.

211301,)! wnsnme'ron, ms'rnroror COLUMBIA; JOBIAEPIEBOI fmou'ron or sun vm'ron U. n. PIERCE, nnosnsnn.

man-oousosnon ENGINE.

To all whom it may concern. 1 Be it known that I, VINTON U. D. Bmnon, a citizen of the United States, residing at Washington, in the-District of Columbia, have invented certain-new and useful Improvements in Internal-Combustion Eng1nes, of which the following is a specificat on, reference being had to the accompanying drawin This Invention relates to internal combustion engines of the four-cycle type, and particularly to means for forcing a charge of fuel into the cylinders of the en e.-

While'this invention is not limited to use with internal combustion engines'desig'ned for the repulsion of aircraft, it is particularly esigned for this urpose for the reason that one of the pro lems in the design of aircraft engines is to secure a maximum of horse power with a minimum of Weight. v a

A further object in the design of engines for aircraft is to keep the engine as siln Is as possible and depart as little as POSSI 1e from the standard construction.

To this end, the neral object of my invention is the provision of means whereby gas to an amount greater than the cub c capacity of the cyhnder ma be positively forced into the cylinder on t e intake stroke of the piston thereof, the cylinder, however, being made with twice the clearance space of an ordinary cylinder having the same capacity so that al compresslon will not be increased, but so that the charge Will be largely increased for each cylinder and the force of the explosion there om largely increased with an increase in the resu ta'nt horse wer.

A rther object is to provide means to this end which while increasing the horse power to a relatively large extent, will not increase the weight of the engine or the complication of the engine proportionately.

Other objects wi 1 appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is a vertical sectional view through an engine constructed in accordance with my invention; and

Figure 2 is an end elevation of the engine shown in Figure 1.

It is to be'understood that the figures above referred to are very largely diagram- Application fledluly 5,

1917. Serial No. 178,882.

matic and are merely intended to illustrate the principle of my invention, it being obvious that the mechanism whereby this principle is carried into efl'ect will be variously modified to suit different circumstances ofcylinder, and each cylinder should have a capacity such that approximately twice the ordinary charge should be compressible within the cylinders without, however, increasin the degree of final compression. Thus t e clearance space between the piston and the head of the cylinder will be larger than the clearance space normally or ordinarily found in internal combustion engines between the head and the piston. This clearance space is proportionately greater than the clearance space normal to normal cylinders of the same capacity, as the pump cylinder is greater in cubic capac ity than the engine cylinder.

Di osed in conjunction with the several cylin ore s a pumping cylinder, desi ated 11. The wallsof this cylinder may relatively light. Operating within this cylinder is a pumpin piston 12, which a so may be relatively ig t. The piston 12 is reciprocated Within the cylinder 11 in any suitable manner and these reciprocations are timed with the reciprocations of the pistons wish to limit myself to any particular means for operating this piston 12 but have shown for this purpose a crank shaft 13, driven in the cylinders A, B, C and D. I do not,

from the main crank shaft 10 by means of a sprocket chain 14. Where four 0 linders are used, the piston 12 should reciprocate twice for each reciprocation of the pistons inthe cylinders A, B, C and D.

The cylinder 11 is connected to a carbureter of an suitable construction, designated 15, an the fuel is drawn first into the cylinder 11, and then dischar ed from the cylinder 11 into successive wor ing cylinders. A valve 16 controls the passage of the fuel from the carburetor into the cylinder 11, this valve, while it may be a check valve or poppet valve being preferably a mechanically operated valve. Thus when the lston 12 moves downward upon its indIICtIOII StI'OkQ, the valve 16 opens or is opened and allows the charge'to pass into the cylinder 11. Upon thereverse movement of the piston 12, the valve 16 closes. A valve 16 controls discharge from cylinder 11.

The c linder 11 is connected to a manifold 17 ywhich a char e is conducted to the several cylinders of t e engine, the discharge of gas into the several cylinders vbeing controlled by inlet valves 18 of any suitable construction, there being one inlet valve for each cylinder. I do not wish to limit myself to the location of the inlet valves, as illustrated, nor to any particular.

provided and these may be of any suitable cylinders A, B, C and D. Thus the cylinder type and as the exhaust valves form no part of my invention,.there is no necessity of particularly describing or illustrating these particular exhaust valves.

The cylinder 11 will have a capacity greater than the capacity of any one of the 11, we will assume, will have a ca city twice that of the cylinders A, B, C an D, or have a capacity three-fourths greater than thecapacity of the cylinders A, B, C and D. This is a matter of design which may he obviously modified to suit any special circumstances or as may be found best in prac-' tice. Assuming that the cylinder 11 has a capacity twice that of the cylinders A, B, C and D, then upon the intake stroke of the piston, in any one of the cylinders, as for instance the cylinder D, the piston 12 will be on its instroke and the contents of the cylinder 11 will be forced into the cylinder D. I referred above to the c linder D as having a ca acity of one-hal that'of the cylinder 11, ut this is not quite right, for the reason that allowance must be made for the clearance so that the cylinder'll will not have quite twice the capacity of the cylinder D. As soon as the piston 12 has completed its stroke and the piston in the cylinder D has completed its out stroke, the valve 16' closes and the valve 18 closes. Upon the next following stroke of the, piston in cylinder D, the nearly double charge in cylinder D will be compressed in the usual manner, but however as the clearance in cylinder D is practically twice that of the c earance ordinarily found in a cylinder of the same capacity, the compression within names-r cylinder D will be no greater than the compression usual in internalcombustion engmes. The charge is then fired in the usual manner. As there is a double charge in the cyhnder, it is obvious that the explosion will have-a much 1' force than with a single char e an a much greater horse power will developed.

While I have referred to the cylinder 11 as havm a capacity nearly double that of any one o the cylinders A, B, G and D, yet it is obvious that it may have a less capacity than that or a greater capacity and that if it be desired to also secure a higher compression, the clearance spam in the several cylinders may be reduced. I believe, however, that it is not'desirable to reduce this clearance space and increase the compression, as this increases the-amount of work which has to be done in order to compress the char and to extent reduces the power of e engine which may be used for doing work.

The degree of com remion is entirely a matter of practice, which. will vary with different types of engines and with different circumstances of o ration.-

The problem in flying machine engines is one of power for engine weight and one solution of this problem has been ofiered in the use of a plurality of inlet and exhaust valves so that a greater amount of fuel may be drawn into the cylinders on each stroke. This, however, has not been entirely satis- 4 factory. Furthermore it is one of the-dc;

siderata of engine constructions that forced induction be used and this is secured by my improvement. It will be seen that'the engine is not increased in weight proportionately to the increase in power, for the reason that only one'cylinder 11 is used for all of the four or more working cylinders A, B, C and D and that this cylinder 11 and the piston operating therein may be of relatively light-construction, because of the fact that there is very little strain on these parts, the fuel only slightly compressed by being for into the cylinder with which the pumping cylinder is temporarily connected, 7

and further it will be seenthat the valve mechanism is of an ordinary type, uite commonly used, and that the means for 'ving the piston 12 may be ofthe simplest character. It is, of course, obvious that there will be an increased consumption of 1 fuel proportionate to the increase in war. Since the pumping'means, namely e cylinder 11 and the piston 12 is a reciprocating pumping means, the current delivered is a engines, I wish it understood that it is also obviously applicable to ordinary automobile engines, power engines and the. engines of motorcraft of all kinds, and that I do not wish to be limited to its with aeroplane or dirigible engines. Neither do I wish to be limited to .the exact: arrangement of valves, nor to the particular construction of valvegear shown.

Having described my invention, what 1 claim is 1. A multiple cylinder multi-cycle internal combustion engine comprising 0 linders and pistons working therein, a, car uretor, and, an independent pumping means geared to operate successively in s chronism with the suction stroke of each piston; said means being connected between said carburetor and cylinders and provided with relatively extended connections whereby substantially complete vaporization of the fuel occurs during the passageof the charge.

2. A multiple cylinder multi-cycle internal combustion engine comprising 0 linders and pistons working therein, a car uretor, and an independent umping means cared to operatesuccessive y to discharge t ereto in synchronism with the suction stroke of each piston; said cylinders being provided with a manifold and connections leading from said. carburetor to said means and from said means to said manifold.

3. A multiple cylinder internal combustion engine comprising cylinders and pistons working therein, a carburetor, an independent reciprocating pumping means, mounted on said engine an connected between said carburetor and cylinders, and mechanical connections driven by said engine arranged to reciprocate said pumpin meanstwice to one of a piston in synchromsm with the suction strokes of the engine pistons whereby charges at pressures in excess of those of the positive pumping capacity of said pistons are drawn in sai cylinders.

4. In a multi le cylinder internal combustion en ine, t e combination with the in take mani old and the carburetor, of recip'-. rocatin the carburetor and the manifold and controlled by the engine to operate in synchronism on its compression stroke with the suction strokes of the pistons of the respective cylinders to discharge -thereinto and arranged to provide a maximum pressure in the manifold at each of the said strokes.

5. In a multiple 0 linder internal combustion engine, the com ination with'the carburetor and the intake manifold, of pumpin means arranged betweenthe carburetor an the manifold, and delivering a pulsating current to the manifold whose periods of maximum pressure are timed to coincide with the charging of the cylinders.

In testimony whereof I hereunto afiix my signature.

VINTON U. 1). PIERCE.

pumping means arranged between 

